There is known an electric toothbrush of a type which performs toothbrushing (removing plaque) by placing a fast-vibrating brush against a tooth surface. For the electric toothbrush of this type, a variety of driving mechanisms and driving methods are proposed with the aim of improving plaque removing power and improving sense of medical treatment.
For example, an electric toothbrush is commercially available which uses a technique of maximizing a frequency amplitude characteristic using mechanical resonance.
Patent Document 1 discloses an electrical toothbrush in which the motor of the electric toothbrush is switched between forward rotation and backward rotation at intervals of 1-10 seconds. When switching takes place about once to five times, the operation of the brush is temporarily stopped or is changed in strength, thereby allowing the users to grasp the time during which they brush their teeth.
Furthermore, there exists an electric toothbrush having a massage mode in which the frequency of the electric toothbrush is successively changed.    Patent Document 1: Japanese Patent Application National Publication No. 8-140738